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Class-D amps - a different re view

Martin Colloms, the editor of HiFi Critic (ad-free mag from the UK) have recently published the review of several different Class-D amps, together with an in depth technical analysys and measurments.

His conclusions were not favourable, to say at least:

"I regret that not a single model merits unqualified recommendation. Price is not the issue; the poor listening tests speak for themselves. (...)
At present we have to take the prudent view that good sound might be possible from switching amps, but we haven't heard it yet."

BelCanto REF1000 (ICEpower) - score 10.5 pooints
"The ICE power module used has a dependable reputation, and the design is well built and finished as a whole. While I would not suggest that you shouldn't try this amp, on sound quality grounds alone I cannot recommend it for audiophile use."

Channel Islands D100 (UcD) - score 13 pooints
"While I have reservations about a number of aspects of sound quality, and advise personal audition, given the solid lab results (...) the overall performance and the moderate price, these CA Audio monos do make it to the 'worth considering' cathegory."

NuForce 8.5V2 (proprietary technology) - score 9 pooints
"Yes, the price is good for the power output. Yes it's pretty, light, small and runs cool. However, the sound quality simply does not justify recommendation." (on top of that the NuForce amp measured very poorly - Elb)

Pro-Ject Amp Box (Flying Mole) - score 5 points
"I'm sorry to say that Project (...) was a real disappointment in the listening tests, and can't be recommended."

Just as a point of reference, recently reviewed Krell 700CX scored 100 points, CJ Premier 350 - 110 points and ARC Ref 110 - 135 points.

At least someone have had the balls to say it. This is why HiFi Critic is THE mag to subscribe.
128x128elberoth2

Showing 10 responses by dazzdax

dazzdax
599 posts
 
I have had a Mark Levinson 333 once that I replaced with an Accuphase A-50V (a well known class A poweramp). The Accuphase was better and more musical than the ML. In 2005 I decided to buy these Acoustic Reality amps with the ICEpower ASP1000 modules (factory direct, so no audition prior to purchase). After extended break in I preferred the sound of the AR amps and sold the Accuphase! A Swedish fellow audiophile bought the Accuphase and is very happy with it. I'm still using the ICEpower amps (now in an upgraded version) and am awaiting a pair of Soundlab A-1 to arrive.
You can regard this ICEpower amp as sh*t. If this is really sh*t then my hearing is shitty too and I don't deserve those A-1's. I would say you should trust Martin Colloms' golden ears, because those are the most audiophile ears on this planet!

Chris
dazzdax
599 posts
 
Vince, haven't you ever heard of Ralph's amplifier brand (Atmasphere)? :)

Ralph: my ICEpower based amps (ASP1000) have a bit aggressive and forward sounding treble. Do you know a cure for this? Will it sound better when I would use some kind of autoformer like the one from Paul Speltz (Anticable, Zero autoformer). Sorry, I'm not a techie so I can be totally wrong...
Btw, my current speakers are Dunlavy SC-V's.

Chris
dazzdax
599 posts
 
Mrtennis: And a vintage tube amp will never sound like a class D amp...

Chris
dazzdax
599 posts
 
Coffeey: "Sure they can sound good,but why oh why did they all get such a terrible low score?Not even in the 40's ,50's,what 8,10.13?Mid fi at best"

I think "4" might be better. Then the Accuphase A-50V should have a "3" and the Mark Levinson 333 a "2" :)

Chris
dazzdax
599 posts
 
Kijanki, thank you for your clear explanation. I'm affraid Martin Colloms should go back to school. If he is not chicken he should also give his response! :)

Chris
dazzdax
599 posts
 
I think Kijanki is right: Martin Colloms' statements about the 17 weak points of class D have no solid scientific foundation. I wonder where he gets such information.

Chris
dazzdax
599 posts
 
Imho Martin Colloms should make apologies because he tried to disqualified class D amps by using pseudo scientific arguments that underlie his lack of knowledge. This is funny: What would Mr. Colloms do if class D was the only type of amplification? Kill himself? :)

Chris
dazzdax
599 posts
 
Branimir, it is not a question whether class D fans are die hards or not. I'm not a die hard and I'm not a class D "fan" either. I'm only reporting my personal experience with class D (ICEpower ASP1000) so far. I'm still convinced that some conventional power amps are superior to all the class D offerings.

Chris
dazzdax
599 posts
 
Elberoth, I like the ICEpower amps better than the Mark Levinson 333 or the Accuphase A-50V. Not because I like "sterile" sounding ICEpower. To me the ICEpower amps sound more transparent, dynamic, faster and less colored compared to the artificial ("mechanical") sounding ML or the slow and a bit opaque sounding Accuphase. This is certainly not hyperbole, this is my own experience, which is somewhat comparable to the experience of the fellow audiophile who preferred ICEpower than his ML 33H's! Or is it likely that we are suffering hearing impairment?

Chris
dazzdax
599 posts
 
One question remains: does a class D amp (in my case the ICEpower amp) sound "bland" and "threadbare" because of lack of harmonic overtones (incapability of reproducing the correct harmonic structure) or does it have to do with lack of distortion? My previous Accuphase A-50V sounded somewhat veiled and opaque in comparison with the ICEpower amp and I've always thought that this is due to "transformer haze", because that's the same type of sound I hear from top of the line Jungson, Marantz and older ML designs.

Chris
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